#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
-#include "hashtable.h"
-#include <cstring>
-#include <cstdio>
-#include "snapshot.h"
-#include "snapshotimp.h"
-#include "mymemory.h"
-#include <fcntl.h>
-#include <assert.h>
-#include <pthread.h>
-#include <semaphore.h>
+#include <string.h>
#include <errno.h>
#include <sys/wait.h>
#include <ucontext.h>
+#include "hashtable.h"
+#include "snapshot.h"
+#include "snapshotimp.h"
+#include "mymemory.h"
#include "common.h"
-#define FAILURE(mesg) { printf("failed in the API: %s with errno relative message: %s\n", mesg, strerror( errno ) ); exit(EXIT_FAILURE); }
+#define FAILURE(mesg) { model_print("failed in the API: %s with errno relative message: %s\n", mesg, strerror(errno)); exit(EXIT_FAILURE); }
#ifdef CONFIG_SSDEBUG
-#define SSDEBUG printf
+#define SSDEBUG model_print
#else
#define SSDEBUG(...) do { } while (0)
#endif
/* extern declaration definition */
-struct SnapShot * snapshotrecord = NULL;
+struct SnapShot *snapshotrecord = NULL;
+
+/** PageAlignedAdressUpdate return a page aligned address for the
+ * address being added as a side effect the numBytes are also changed.
+ */
+static void * PageAlignAddressUpward(void *addr)
+{
+ return (void *)((((uintptr_t)addr) + PAGESIZE - 1) & ~(PAGESIZE - 1));
+}
#if !USE_MPROTECT_SNAPSHOT
/** @statics
static ucontext_t savedSnapshotContext;
static ucontext_t savedUserSnapshotContext;
static snapshot_id snapshotid = 0;
-#endif
-
-/** PageAlignedAdressUpdate return a page aligned address for the
- * address being added as a side effect the numBytes are also changed.
- */
-static void * PageAlignAddressUpward(void * addr) {
- return (void *)((((uintptr_t)addr)+PAGESIZE-1)&~(PAGESIZE-1));
-}
-#if USE_MPROTECT_SNAPSHOT
+#else /* USE_MPROTECT_SNAPSHOT */
/** ReturnPageAlignedAddress returns a page aligned address for the
* address being added as a side effect the numBytes are also changed.
*/
-static void * ReturnPageAlignedAddress(void * addr) {
- return (void *)(((uintptr_t)addr)&~(PAGESIZE-1));
+static void * ReturnPageAlignedAddress(void *addr)
+{
+ return (void *)(((uintptr_t)addr) & ~(PAGESIZE - 1));
}
/** The initSnapShotRecord method initialized the snapshotting data
* structures for the mprotect based snapshot.
*/
-static void initSnapShotRecord(unsigned int numbackingpages, unsigned int numsnapshots, unsigned int nummemoryregions) {
- snapshotrecord=( struct SnapShot * )model_malloc(sizeof(struct SnapShot));
- snapshotrecord->regionsToSnapShot=( struct MemoryRegion * )model_malloc(sizeof(struct MemoryRegion)*nummemoryregions);
- snapshotrecord->backingStoreBasePtr= ( struct SnapShotPage * )model_malloc( sizeof( struct SnapShotPage ) * (numbackingpages + 1) );
+static void initSnapShotRecord(unsigned int numbackingpages, unsigned int numsnapshots, unsigned int nummemoryregions)
+{
+ snapshotrecord = (struct SnapShot *)model_malloc(sizeof(struct SnapShot));
+ snapshotrecord->regionsToSnapShot = (struct MemoryRegion *)model_malloc(sizeof(struct MemoryRegion) * nummemoryregions);
+ snapshotrecord->backingStoreBasePtr = (struct SnapShotPage *)model_malloc(sizeof(struct SnapShotPage) * (numbackingpages + 1));
//Page align the backingstorepages
- snapshotrecord->backingStore=( struct SnapShotPage * )PageAlignAddressUpward(snapshotrecord->backingStoreBasePtr);
- snapshotrecord->backingRecords=( struct BackingPageRecord * )model_malloc(sizeof(struct BackingPageRecord)*numbackingpages);
- snapshotrecord->snapShots= ( struct SnapShotRecord * )model_malloc(sizeof(struct SnapShotRecord)*numsnapshots);
- snapshotrecord->lastSnapShot=0;
- snapshotrecord->lastBackingPage=0;
- snapshotrecord->lastRegion=0;
- snapshotrecord->maxRegions=nummemoryregions;
- snapshotrecord->maxBackingPages=numbackingpages;
- snapshotrecord->maxSnapShots=numsnapshots;
+ snapshotrecord->backingStore = (struct SnapShotPage *)PageAlignAddressUpward(snapshotrecord->backingStoreBasePtr);
+ snapshotrecord->backingRecords = (struct BackingPageRecord *)model_malloc(sizeof(struct BackingPageRecord) * numbackingpages);
+ snapshotrecord->snapShots = (struct SnapShotRecord *)model_malloc(sizeof(struct SnapShotRecord) * numsnapshots);
+ snapshotrecord->lastSnapShot = 0;
+ snapshotrecord->lastBackingPage = 0;
+ snapshotrecord->lastRegion = 0;
+ snapshotrecord->maxRegions = nummemoryregions;
+ snapshotrecord->maxBackingPages = numbackingpages;
+ snapshotrecord->maxSnapShots = numsnapshots;
}
/** HandlePF is the page fault handler for mprotect based snapshotting
* algorithm.
*/
-static void HandlePF( int sig, siginfo_t *si, void * unused){
- if( si->si_code == SEGV_MAPERR ){
- printf("Real Fault at %p\n", si->si_addr);
+static void HandlePF(int sig, siginfo_t *si, void *unused)
+{
+ if (si->si_code == SEGV_MAPERR) {
+ model_print("Real Fault at %p\n", si->si_addr);
print_trace();
- exit( EXIT_FAILURE );
+ model_print("For debugging, place breakpoint at: %s:%d\n",
+ __FILE__, __LINE__);
+ exit(EXIT_FAILURE);
}
void* addr = ReturnPageAlignedAddress(si->si_addr);
- unsigned int backingpage=snapshotrecord->lastBackingPage++; //Could run out of pages...
- if (backingpage==snapshotrecord->maxBackingPages) {
- printf("Out of backing pages at %p\n", si->si_addr);
- exit( EXIT_FAILURE );
+ unsigned int backingpage = snapshotrecord->lastBackingPage++; //Could run out of pages...
+ if (backingpage == snapshotrecord->maxBackingPages) {
+ model_print("Out of backing pages at %p\n", si->si_addr);
+ exit(EXIT_FAILURE);
}
//copy page
memcpy(&(snapshotrecord->backingStore[backingpage]), addr, sizeof(struct SnapShotPage));
//remember where to copy page back to
- snapshotrecord->backingRecords[backingpage].basePtrOfPage=addr;
+ snapshotrecord->backingRecords[backingpage].basePtrOfPage = addr;
//set protection to read/write
- if (mprotect( addr, sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE )) {
+ if (mprotect(addr, sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE)) {
perror("mprotect");
// Handle error by quitting?
}
}
-#endif //nothing to handle for non snapshotting case.
+#endif /* USE_MPROTECT_SNAPSHOT */
#if !USE_MPROTECT_SNAPSHOT
-void createSharedMemory(){
+void createSharedMemory()
+{
//step 1. create shared memory.
- void * memMapBase = mmap( 0, SHARED_MEMORY_DEFAULT + STACK_SIZE_DEFAULT, PROT_READ | PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0 );
- if( MAP_FAILED == memMapBase )
+ void *memMapBase = mmap(0, SHARED_MEMORY_DEFAULT + STACK_SIZE_DEFAULT, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+ if (MAP_FAILED == memMapBase)
FAILURE("mmap");
//Setup snapshot record at top of free region
- snapshotrecord = ( struct SnapShot * )memMapBase;
+ snapshotrecord = (struct SnapShot *)memMapBase;
snapshotrecord->mSharedMemoryBase = (void *)((uintptr_t)memMapBase + sizeof(struct SnapShot));
snapshotrecord->mStackBase = (void *)((uintptr_t)memMapBase + SHARED_MEMORY_DEFAULT);
snapshotrecord->mStackSize = STACK_SIZE_DEFAULT;
#endif
-/** The initSnapShotLibrary function initializes the Snapshot library.
+/** The initSnapshotLibrary function initializes the snapshot library.
* @param entryPoint the function that should run the program.
*/
#if USE_MPROTECT_SNAPSHOT
-void initSnapShotLibrary(unsigned int numbackingpages,
+void initSnapshotLibrary(unsigned int numbackingpages,
unsigned int numsnapshots, unsigned int nummemoryregions,
- unsigned int numheappages, VoidFuncPtr entryPoint) {
+ unsigned int numheappages, VoidFuncPtr entryPoint)
+{
/* Setup a stack for our signal handler.... */
stack_t ss;
- ss.ss_sp = model_malloc(SIGSTACKSIZE);
+ ss.ss_sp = PageAlignAddressUpward(model_malloc(SIGSTACKSIZE + PAGESIZE - 1));
ss.ss_size = SIGSTACKSIZE;
ss.ss_flags = 0;
sigaltstack(&ss, NULL);
struct sigaction sa;
sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART | SA_ONSTACK;
- sigemptyset( &sa.sa_mask );
+ sigemptyset(&sa.sa_mask);
sa.sa_sigaction = HandlePF;
#ifdef MAC
- if( sigaction( SIGBUS, &sa, NULL ) == -1 ){
- printf("SIGACTION CANNOT BE INSTALLED\n");
+ if (sigaction(SIGBUS, &sa, NULL) == -1) {
+ model_print("SIGACTION CANNOT BE INSTALLED\n");
exit(EXIT_FAILURE);
}
#endif
- if( sigaction( SIGSEGV, &sa, NULL ) == -1 ){
- printf("SIGACTION CANNOT BE INSTALLED\n");
+ if (sigaction(SIGSEGV, &sa, NULL) == -1) {
+ model_print("SIGACTION CANNOT BE INSTALLED\n");
exit(EXIT_FAILURE);
}
siginfo_t si;
memset(&si, 0, sizeof(si));
- si.si_addr=ss.ss_sp;
+ si.si_addr = ss.ss_sp;
HandlePF(SIGSEGV, &si, NULL);
snapshotrecord->lastBackingPage--; //remove the fake page we copied
- basemySpace=model_malloc((numheappages+1)*PAGESIZE);
- void * pagealignedbase=PageAlignAddressUpward(basemySpace);
- mySpace = create_mspace_with_base(pagealignedbase, numheappages*PAGESIZE, 1 );
+ void *basemySpace = model_malloc((numheappages + 1) * PAGESIZE);
+ void *pagealignedbase = PageAlignAddressUpward(basemySpace);
+ user_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
+ addMemoryRegionToSnapShot(pagealignedbase, numheappages);
+
+ void *base_model_snapshot_space = model_malloc((numheappages + 1) * PAGESIZE);
+ pagealignedbase = PageAlignAddressUpward(base_model_snapshot_space);
+ model_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
addMemoryRegionToSnapShot(pagealignedbase, numheappages);
+
entryPoint();
}
#else
-void initSnapShotLibrary(unsigned int numbackingpages,
+void initSnapshotLibrary(unsigned int numbackingpages,
unsigned int numsnapshots, unsigned int nummemoryregions,
- unsigned int numheappages, VoidFuncPtr entryPoint) {
- basemySpace=system_malloc((numheappages+1)*PAGESIZE);
- void * pagealignedbase=PageAlignAddressUpward(basemySpace);
- mySpace = create_mspace_with_base(pagealignedbase, numheappages*PAGESIZE, 1 );
+ unsigned int numheappages, VoidFuncPtr entryPoint)
+{
if (!snapshotrecord)
createSharedMemory();
+ void *base_model_snapshot_space = malloc((numheappages + 1) * PAGESIZE);
+ void *pagealignedbase = PageAlignAddressUpward(base_model_snapshot_space);
+ model_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
+
//step 2 setup the stack context.
ucontext_t newContext;
- getcontext( &newContext );
+ getcontext(&newContext);
newContext.uc_stack.ss_sp = snapshotrecord->mStackBase;
newContext.uc_stack.ss_size = STACK_SIZE_DEFAULT;
- makecontext( &newContext, entryPoint, 0 );
+ makecontext(&newContext, entryPoint, 0);
/* switch to a new entryPoint context, on a new stack */
swapcontext(&savedSnapshotContext, &newContext);
as the id to which the rollback needs to occur */
bool rollback = false;
- while( true ){
- snapshotrecord->currSnapShotID=snapshotid+1;
+ while (true) {
+ snapshotrecord->currSnapShotID = snapshotid + 1;
forkedID = fork();
- if( 0 == forkedID ){
+ if (0 == forkedID) {
/* If the rollback bool is set, switch to the context we need to
return to during a rollback. */
- if( rollback) {
- setcontext( &( snapshotrecord->mContextToRollback ) );
+ if (rollback) {
+ setcontext(&(snapshotrecord->mContextToRollback));
} else {
/*Child process which is forked as a result of takesnapshot
call should switch back to the takesnapshot context*/
- setcontext( &savedUserSnapshotContext );
+ setcontext(&savedUserSnapshotContext);
}
} else {
int status;
int retVal;
SSDEBUG("The process id of child is %d and the process id of this process is %d and snapshot id is %d\n",
- forkedID, getpid(), snapshotid );
+ forkedID, getpid(), snapshotid);
do {
- retVal=waitpid( forkedID, &status, 0 );
- } while( -1 == retVal && errno == EINTR );
+ retVal = waitpid(forkedID, &status, 0);
+ } while (-1 == retVal && errno == EINTR);
- if( snapshotrecord->mIDToRollback != snapshotid ) {
+ if (snapshotrecord->mIDToRollback != snapshotid) {
exit(EXIT_SUCCESS);
}
rollback = true;
/** The addMemoryRegionToSnapShot function assumes that addr is page aligned.
*/
-void addMemoryRegionToSnapShot( void * addr, unsigned int numPages) {
+void addMemoryRegionToSnapShot(void *addr, unsigned int numPages)
+{
#if USE_MPROTECT_SNAPSHOT
- unsigned int memoryregion=snapshotrecord->lastRegion++;
- if (memoryregion==snapshotrecord->maxRegions) {
- printf("Exceeded supported number of memory regions!\n");
+ unsigned int memoryregion = snapshotrecord->lastRegion++;
+ if (memoryregion == snapshotrecord->maxRegions) {
+ model_print("Exceeded supported number of memory regions!\n");
exit(EXIT_FAILURE);
}
- snapshotrecord->regionsToSnapShot[ memoryregion ].basePtr=addr;
- snapshotrecord->regionsToSnapShot[ memoryregion ].sizeInPages=numPages;
+ snapshotrecord->regionsToSnapShot[memoryregion].basePtr = addr;
+ snapshotrecord->regionsToSnapShot[memoryregion].sizeInPages = numPages;
#endif //NOT REQUIRED IN THE CASE OF FORK BASED SNAPSHOTS.
}
/** The takeSnapshot function takes a snapshot.
* @return The snapshot identifier.
*/
-snapshot_id takeSnapshot( ){
+snapshot_id takeSnapshot()
+{
#if USE_MPROTECT_SNAPSHOT
- for(unsigned int region=0; region<snapshotrecord->lastRegion;region++) {
- if( mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages*sizeof(struct SnapShotPage), PROT_READ ) == -1 ){
+ for (unsigned int region = 0; region < snapshotrecord->lastRegion; region++) {
+ if (mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages * sizeof(struct SnapShotPage), PROT_READ) == -1) {
perror("mprotect");
- printf("Failed to mprotect inside of takeSnapShot\n");
+ model_print("Failed to mprotect inside of takeSnapShot\n");
exit(EXIT_FAILURE);
}
}
- unsigned int snapshot=snapshotrecord->lastSnapShot++;
- if (snapshot==snapshotrecord->maxSnapShots) {
- printf("Out of snapshots\n");
+ unsigned int snapshot = snapshotrecord->lastSnapShot++;
+ if (snapshot == snapshotrecord->maxSnapShots) {
+ model_print("Out of snapshots\n");
exit(EXIT_FAILURE);
}
- snapshotrecord->snapShots[snapshot].firstBackingPage=snapshotrecord->lastBackingPage;
+ snapshotrecord->snapShots[snapshot].firstBackingPage = snapshotrecord->lastBackingPage;
return snapshot;
#else
- swapcontext( &savedUserSnapshotContext, &savedSnapshotContext );
+ swapcontext(&savedUserSnapshotContext, &savedSnapshotContext);
SSDEBUG("TAKESNAPSHOT RETURN\n");
return snapshotid;
#endif
/** The rollBack function rollback to the given snapshot identifier.
* @param theID is the snapshot identifier to rollback to.
*/
-void rollBack( snapshot_id theID ){
+void rollBack(snapshot_id theID)
+{
+#if USE_MPROTECT_SNAPSHOT == 2
+ if (snapshotrecord->lastSnapShot == (theID + 1)) {
+ for (unsigned int page = snapshotrecord->snapShots[theID].firstBackingPage; page < snapshotrecord->lastBackingPage; page++) {
+ memcpy(snapshotrecord->backingRecords[page].basePtrOfPage, &snapshotrecord->backingStore[page], sizeof(struct SnapShotPage));
+ }
+ return;
+ }
+#endif
+
#if USE_MPROTECT_SNAPSHOT
- HashTable< void *, bool, uintptr_t, 4, model_malloc, model_calloc, MYFREE> duplicateMap;
- for(unsigned int region=0; region<snapshotrecord->lastRegion;region++) {
- if( mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages*sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE ) == -1 ){
+ HashTable< void *, bool, uintptr_t, 4, model_malloc, model_calloc, model_free> duplicateMap;
+ for (unsigned int region = 0; region < snapshotrecord->lastRegion; region++) {
+ if (mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages * sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE) == -1) {
perror("mprotect");
- printf("Failed to mprotect inside of takeSnapShot\n");
+ model_print("Failed to mprotect inside of takeSnapShot\n");
exit(EXIT_FAILURE);
}
}
- for(unsigned int page=snapshotrecord->snapShots[theID].firstBackingPage; page<snapshotrecord->lastBackingPage; page++) {
- if( !duplicateMap.contains(snapshotrecord->backingRecords[page].basePtrOfPage )) {
+ for (unsigned int page = snapshotrecord->snapShots[theID].firstBackingPage; page < snapshotrecord->lastBackingPage; page++) {
+ if (!duplicateMap.contains(snapshotrecord->backingRecords[page].basePtrOfPage)) {
duplicateMap.put(snapshotrecord->backingRecords[page].basePtrOfPage, true);
memcpy(snapshotrecord->backingRecords[page].basePtrOfPage, &snapshotrecord->backingStore[page], sizeof(struct SnapShotPage));
}
}
- snapshotrecord->lastSnapShot=theID;
- snapshotrecord->lastBackingPage=snapshotrecord->snapShots[theID].firstBackingPage;
+ snapshotrecord->lastSnapShot = theID;
+ snapshotrecord->lastBackingPage = snapshotrecord->snapShots[theID].firstBackingPage;
takeSnapshot(); //Make sure current snapshot is still good...All later ones are cleared
#else
snapshotrecord->mIDToRollback = theID;
volatile int sTemp = 0;
- getcontext( &snapshotrecord->mContextToRollback );
+ getcontext(&snapshotrecord->mContextToRollback);
/*
* This is used to quit the process on rollback, so that the process
* which needs to rollback can quit allowing the process whose
* snapshotid matches the rollbackid to switch to this context and
* continue....
*/
- if( !sTemp ){
+ if (!sTemp) {
sTemp = 1;
SSDEBUG("Invoked rollback\n");
exit(EXIT_SUCCESS);
}
/*
* This fix obviates the need for a finalize call. hence less dependences for model-checker....
- *
*/
snapshotrecord->mIDToRollback = -1;
#endif
}
-